1. Field of the invention
The present invention relates to a zoom lens system which is suited for use with video cameras.
2. Description of the prior art
In the recent years, there are produced strong demands for zoom lens systems which are to be used with video cameras. Further, it has conventionally been desired to configure zoom lens systems so as to be compacter. Furthermore, it is increasingly demanded to configure zoom lens systems so as to have wider field angles and higher vari-focal ratios. Out of the conventional zoom lens systems which are to be used with video cameras, the demands or requirements described above are satisfied only by a zoom lens system disclosed by Japanese Patent Kokai Publication No. Hei 3-215,810. However, this zoom lens system has a vari-focal ratio on the order of 8 and a half field angle on the order of 56.degree. which cannot be said as a sufficiently high vari-focal ratio and a sufficiently wide field angle respectively.
The conventional zoom lens systems have compositions which do not permit obtaining a higher vari-focal ratio or a wider field angle.